How long is a normal PR interval measured in seconds?

The normal duration of a PR interval is measured between 0.12 to 0.20 seconds. This interval represents the time between the onset of atrial depolarization and the onset of ventricular depolarization. Essentially, it includes the time taken for the electrical impulse to travel from the atria to the ventricles through the AV node.

When the PR interval falls within the range of 0.12 to 0.20 seconds, it indicates that the conduction from the atria to the ventricles is functioning normally, which is critical for coordinated heartbeat. If the interval is shorter or longer than this norm, it could indicate various forms of heart disease or conduction abnormalities that need to be evaluated further.

Thus, recognizing the correct interval is vital for interpreting EKGs accurately and understanding the functionality of the heart's electrical conduction system.